420 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
seem plausible but a critical examination indicates that it is 
highly improbable if not impossible, since the edges of the tarsal 
joints are not specially sharp, are not closely applied to the tibial 
projections, and the leverage is extremely poor. On the contrary, 
there can be little question that it is done by the efficient shear- 
like action of the powerful mandibles. 
If this Cricket still exists on the island it should be possible 
to detect its presence by its song, which is probably sufficiently 
distinctive to differentiate it from that of our native species, 
which is also found there. 
Pygmy Mole-cricket. 
Tridactylus apicialis Say. 
Figs. 76, 77. 
Tridactylus apicialis Say, Journ. Acad. Nat. Sci. Phila., ser. 1, vol. 4, p. 310 
(1825).— ScxjDDER, Boston Journ. Nat. Hist., vol. 7, p. 425 (1862). 
Tridactylus terminalis Sctjdder, Boston Journ. Nat. Hist., vol. 7, p. 425 
(1862).— Fernald, Orth. N. E., p. 13 (1888).— Smith, Rept. Ct. Bd. 
Agric. for 1872, p. 380 (1873).— Morse, Psyche, vol. 9, p. 197 (1901).— 
Walden, Bull. Geol. Nat. Hist. Surv. Ct., no. 16, p. 150 (1911). 
Head rounded, smooth. Pronotum as wide as long, its front 
margin straight, hind margin a little convex, lateral margins con- 
cave, front and hind angles about rectangular. The wings pass 
the end of the body about 1 mm. Tegmina half as long as wings, 
alike in both sexes. Stridulatory organs not visible. Hind 
femora very large, reaching end of body, elongate elliptic, more 
than one-third as wide as long. Hind tarsi reduced to a single 
joint appressed to the hind tibiae when at rest; tibial spurs as long 
as tarsal joint, directed forward when at rest. 
The fore legs are the shortest of the three pairs and in the female 
are rather stout. The front tibia is somewhat ovate in outline, 
and bears distally four prominent, equidistant teeth; its convex 
hinder face is thickly set with hairs and bears a row of spinous 
hairs on the outer margin, the very slender tarsus being inserted 
between the first and second teeth and lying in a recess on the 
anterior surface of the tibia. This description of the tibia ap- 
plies also to some males. In others a remarkable bifurcation is 
present, the tibia loses its hairy covering, the innermost tooth 
nearly disappears, the second is greatly prolonged, the branch that 
